Some pet owners are advocating against rabies vaccines. Here's why rabies is dangerous.

Hesitancy around vaccines has spilled over to pet owners in recent years, sparking concern about the resurgence of rabies, a virus that's nearly always fatal.

Some pet owners argue against vaccinating dogs – over concerns that vaccines shorten the canines' lifespans or beliefs that vaccines can cause autism in dogs. But autism's spectrum of symptoms is uniquely human and experts say anti-vaxxing campaigns among dog owners are especially dangerous considering the public health consequences of rabies.

“While, thankfully, we don’t see a lot of rabies, the consequence is disastrous,” Dr. Rena Carlson, president of the American Veterinary Medical Association, told USA TODAY. “It’s essentially 100% fatal. So having a rabies vaccine for your cat and dog is really, really important on many levels.”

Carlson stressed how important it is for people to talk with their veterinarians about the vaccine and the risks a pet faces if it does not get vaccinated.

What is rabies?

Rabies spreads when an infected animal bites or scratches someone, invading mammals’ nervous systems. The virus becomes especially dangerous when it reaches the brain. The incubation period can last days or more than a year.

When rabies enters the brain, it causes flu-like symptoms that cause animals to become rabid, and develop brain swelling. The disease becomes fatal when an infected person or animal suddenly loses breathing and heart function.

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The risks of not vaccinating for the disease apparently do not resonate with some pet owners.

Matt Motta, an assistant professor at Boston University School of Public Health, calls it a “spillover effect” among people hesitant about human vaccines, a population that ballooned during the COVID-19 pandemic. He worries that "canine vaccine hesitancy" could grow in states that mandate rabies vaccines. If those laws are dismantled, it would threaten decades-old health initiatives that have proven successful.

“We could see a situation where more and more dogs are unvaccinated,” he told USA TODAY. “That poses a public health threat to not just our pets, but all of us.”

Motta and his sister, Dr. Gabriella Motta, a Pennsylvania veterinarian, published a 2023 study that found that nearly 40% of U.S. dog owners believe canine vaccines are unsafe. About 37% of owners thought their dogs could develop autism from vaccination.

The reality, Motta says, is the rabies vaccine is safe.

About 2 in 1 million dogs get severe complications from a vaccine.

Dog autism isn’t a recognized condition, the American Veterinary Medical Association and the Centers for Disease Control and Prevention told USA TODAY. The notion that the human measles, mumps and rubella vaccine causes autism in children has long been disproven. However, it continues to hold sway, causing some people to refuse to vaccinate their children. This avoidance contributed to several recent outbreaks, according to public officials, who issued warnings and said vaccines are vital for community health. The avoidance of pet vaccines follows a similar pattern.

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Like they did with measles, health officials worked for decades to eradicate canine rabies, a variant specific to dogs. Successful public health campaigns included leash laws, the use of animal shelters and vaccinations. Rabies variants in North American wildlife still circulate and can infect dogs.

Rabid dogs remain a concern internationally: nearly all people who die from rabies get it from dog bites. There are typically about 59,000 deaths annually.

Dr. Ryan Wallace, the leader of CDC’s rabies program, said about 75 million dogs have been vaccinated over a recent three-year period, which means there doesn’t appear to be a drop-off in vaccinations despite the shift in opinion. The American Veterinary Medical Association, like the CDC, hasn’t seen a major decline in vaccinations, although the numbers are hard to track.

Wallace said it's important to distinguish between people’s perceptions about pet vaccines, with some expressing hesitancy, and the firm mandates that require dogs to be vaccinated in most states, which pet owners, for the most part, appear to abide by nonetheless.

A common issue in public health is that when systems work, people don’t see problems in front of them. While there are few rabies deaths in the U.S. – about one to three per year – there are 60,000 Americans who have gotten a rabies vaccine after contact with an animal they suspected was rabid. And rabies still circulates among wild animals.

“We focus on how many of these rare deaths occurred,” he said, "but the focus should really be on how often people and their pets are getting exposed to rabid animals. Because they're all over.”

This article originally appeared on USA TODAY: Anti-vax pet owners opposing rabies shot. That's concerning to vets.